Well, I have a clyde cross, who is the easiest horse I have ever owned. He gets less than a cup of pellets 2x/day just for supplements, and pretty much free choice hay, which at times we have to limit since he gets too roly poly. Never had shoes, feet are great. I also have a friend with 2 perch crosses, both of whom are fabulous, and she teaches mounted police clinics with them.
My experience-LOVE THEM! Truly Gentle giants.
I do agree that it depend on how much has been done as far as backing. If he has done a little ring work on the flat, I would not have an issue, and would guess it would be fine.